diff --git a/features/test/notify_reasons_test.py b/features/test/notify_reasons_test.py
new file mode 100644
index 0000000..559e322
--- /dev/null
+++ b/features/test/notify_reasons_test.py
@@ -0,0 +1,407 @@
+# Copyright 2017 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file or at
+# https://developers.google.com/open-source/licenses/bsd
+
+"""Tests for notify_reasons.py."""
+from __future__ import print_function
+from __future__ import division
+from __future__ import absolute_import
+
+import unittest
+import os
+
+from features import notify_reasons
+from framework import emailfmt
+from framework import framework_views
+from framework import urls
+from proto import user_pb2
+from proto import usergroup_pb2
+from services import service_manager
+from testing import fake
+from tracker import tracker_bizobj
+
+
+REPLY_NOT_ALLOWED = notify_reasons.REPLY_NOT_ALLOWED
+REPLY_MAY_COMMENT = notify_reasons.REPLY_MAY_COMMENT
+REPLY_MAY_UPDATE = notify_reasons.REPLY_MAY_UPDATE
+
+
+class ComputeIssueChangeAddressPermListTest(unittest.TestCase):
+
+  def setUp(self):
+    self.users_by_id = {
+        111: framework_views.StuffUserView(111, 'owner@example.com', True),
+        222: framework_views.StuffUserView(222, 'member@example.com', True),
+        999: framework_views.StuffUserView(999, 'visitor@example.com', True),
+        }
+    self.services = service_manager.Services(
+        project=fake.ProjectService(),
+        config=fake.ConfigService(),
+        issue=fake.IssueService(),
+        user=fake.UserService(),
+        usergroup=fake.UserGroupService())
+    self.owner = self.services.user.TestAddUser('owner@example.com', 111)
+    self.member = self.services.user.TestAddUser('member@example.com', 222)
+    self.visitor = self.services.user.TestAddUser('visitor@example.com', 999)
+    self.project = self.services.project.TestAddProject(
+        'proj', owner_ids=[111], committer_ids=[222])
+    self.project.process_inbound_email = True
+    self.issue = fake.MakeTestIssue(
+        self.project.project_id, 1, 'summary', 'New', 111)
+
+  def testEmptyIDs(self):
+    cnxn = 'fake cnxn'
+    addr_perm_list = notify_reasons.ComputeIssueChangeAddressPermList(
+        cnxn, [], self.project, self.issue, self.services, [], {})
+    self.assertEqual([], addr_perm_list)
+
+  def testRecipientIsMember(self):
+    cnxn = 'fake cnxn'
+    ids_to_consider = [111, 222, 999]
+    addr_perm_list = notify_reasons.ComputeIssueChangeAddressPermList(
+        cnxn, ids_to_consider, self.project, self.issue, self.services, set(),
+        self.users_by_id, pref_check_function=lambda *args: True)
+    self.assertEqual(
+        [notify_reasons.AddrPerm(
+            True, 'owner@example.com', self.owner, REPLY_MAY_UPDATE,
+            user_pb2.UserPrefs(user_id=111)),
+         notify_reasons.AddrPerm(
+            True, 'member@example.com', self.member, REPLY_MAY_UPDATE,
+            user_pb2.UserPrefs(user_id=222)),
+         notify_reasons.AddrPerm(
+            False, 'visitor@example.com', self.visitor, REPLY_MAY_COMMENT,
+            user_pb2.UserPrefs(user_id=999))],
+        addr_perm_list)
+
+
+class ComputeProjectAndIssueNotificationAddrListTest(unittest.TestCase):
+
+  def setUp(self):
+    self.cnxn = 'fake cnxn'
+    self.services = service_manager.Services(
+        project=fake.ProjectService(),
+        user=fake.UserService())
+    self.project = self.services.project.TestAddProject('project')
+    self.services.user.TestAddUser('alice@gmail.com', 111)
+    self.services.user.TestAddUser('bob@gmail.com', 222)
+    self.services.user.TestAddUser('fred@gmail.com', 555)
+
+  def testNotifyAddress(self):
+    # No mailing list or filter rules are defined
+    addr_perm_list = notify_reasons.ComputeProjectNotificationAddrList(
+        self.cnxn, self.services, self.project, True, set())
+    self.assertListEqual([], addr_perm_list)
+
+    # Only mailing list is notified.
+    self.project.issue_notify_address = 'mailing-list@domain.com'
+    addr_perm_list = notify_reasons.ComputeProjectNotificationAddrList(
+        self.cnxn, self.services, self.project, True, set())
+    self.assertListEqual(
+        [notify_reasons.AddrPerm(
+            False, 'mailing-list@domain.com', None, REPLY_NOT_ALLOWED,
+            user_pb2.UserPrefs())],
+        addr_perm_list)
+
+    # No one is notified because mailing list was already notified.
+    omit_addrs = {'mailing-list@domain.com'}
+    addr_perm_list = notify_reasons.ComputeProjectNotificationAddrList(
+        self.cnxn, self.services, self.project, False, omit_addrs)
+    self.assertListEqual([], addr_perm_list)
+
+    # No one is notified because anon users cannot view.
+    addr_perm_list = notify_reasons.ComputeProjectNotificationAddrList(
+        self.cnxn, self.services, self.project, False, set())
+    self.assertListEqual([], addr_perm_list)
+
+  def testFilterRuleNotifyAddresses(self):
+    issue = fake.MakeTestIssue(
+        self.project.project_id, 1, 'summary', 'New', 555)
+    issue.derived_notify_addrs.extend(['notify@domain.com'])
+
+    addr_perm_list = notify_reasons.ComputeIssueNotificationAddrList(
+        self.cnxn, self.services, issue, set())
+    self.assertListEqual(
+        [notify_reasons.AddrPerm(
+            False, 'notify@domain.com', None, REPLY_NOT_ALLOWED,
+            user_pb2.UserPrefs())],
+        addr_perm_list)
+
+    # Also-notify addresses can be omitted (e.g., if it is the same as
+    # the email address of the user who made the change).
+    addr_perm_list = notify_reasons.ComputeIssueNotificationAddrList(
+        self.cnxn, self.services, issue, {'notify@domain.com'})
+    self.assertListEqual([], addr_perm_list)
+
+
+class ComputeGroupReasonListTest(unittest.TestCase):
+
+  def setUp(self):
+    self.services = service_manager.Services(
+        project=fake.ProjectService(),
+        config=fake.ConfigService(),
+        issue=fake.IssueService(),
+        features=fake.FeaturesService(),
+        user=fake.UserService(),
+        usergroup=fake.UserGroupService())
+    self.project = self.services.project.TestAddProject(
+      'project', project_id=789)
+    self.config = self.services.config.GetProjectConfig('cnxn', 789)
+    self.alice = self.services.user.TestAddUser('alice@example.com', 111)
+    self.bob = self.services.user.TestAddUser('bob@example.com', 222)
+    self.fred = self.services.user.TestAddUser('fred@example.com', 555)
+    self.users_by_id = framework_views.MakeAllUserViews(
+        'cnxn', self.services.user, [111, 222, 555])
+    self.issue = fake.MakeTestIssue(
+        self.project.project_id, 1, 'summary', 'New', 555)
+
+  def CheckGroupReasonList(
+      self,
+      actual,
+      reporter_apl=None,
+      owner_apl=None,
+      old_owner_apl=None,
+      default_owner_apl=None,
+      ccd_apl=None,
+      group_ccd_apl=None,
+      default_ccd_apl=None,
+      starrer_apl=None,
+      subscriber_apl=None,
+      also_notified_apl=None,
+      all_notifications_apl=None):
+    (
+        you_report, you_own, you_old_owner, you_default_owner, you_ccd,
+        you_group_ccd, you_default_ccd, you_star, you_subscribe,
+        you_also_notify, all_notifications) = actual
+    self.assertEqual(
+        (reporter_apl or [], notify_reasons.REASON_REPORTER),
+        you_report)
+    self.assertEqual(
+        (owner_apl or [], notify_reasons.REASON_OWNER),
+        you_own)
+    self.assertEqual(
+        (old_owner_apl or [], notify_reasons.REASON_OLD_OWNER),
+        you_old_owner)
+    self.assertEqual(
+        (default_owner_apl or [], notify_reasons.REASON_DEFAULT_OWNER),
+        you_default_owner)
+    self.assertEqual(
+        (ccd_apl or [], notify_reasons.REASON_CCD),
+        you_ccd)
+    self.assertEqual(
+        (group_ccd_apl or [], notify_reasons.REASON_GROUP_CCD), you_group_ccd)
+    self.assertEqual(
+        (default_ccd_apl or [], notify_reasons.REASON_DEFAULT_CCD),
+        you_default_ccd)
+    self.assertEqual(
+        (starrer_apl or [], notify_reasons.REASON_STARRER),
+        you_star)
+    self.assertEqual(
+        (subscriber_apl or [], notify_reasons.REASON_SUBSCRIBER),
+        you_subscribe)
+    self.assertEqual(
+        (also_notified_apl or [], notify_reasons.REASON_ALSO_NOTIFY),
+        you_also_notify)
+    self.assertEqual(
+        (all_notifications_apl or [], notify_reasons.REASON_ALL_NOTIFICATIONS),
+        all_notifications)
+
+  def testComputeGroupReasonList_OwnerAndCC(self):
+    """Fred owns the issue, Alice is CC'd."""
+    self.issue.cc_ids = [self.alice.user_id]
+    actual = notify_reasons.ComputeGroupReasonList(
+        'cnxn', self.services, self.project, self.issue, self.config,
+        self.users_by_id, [], True)
+    self.CheckGroupReasonList(
+        actual,
+        owner_apl=[notify_reasons.AddrPerm(
+            False, self.fred.email, self.fred, REPLY_NOT_ALLOWED,
+            user_pb2.UserPrefs(user_id=self.fred.user_id))],
+        ccd_apl=[notify_reasons.AddrPerm(
+            False, self.alice.email, self.alice, REPLY_NOT_ALLOWED,
+            user_pb2.UserPrefs(user_id=self.alice.user_id))])
+
+  def testComputeGroupReasonList_DerivedCcs(self):
+    """Check we correctly compute reasons for component and rule ccs."""
+    member_1 = self.services.user.TestAddUser('member_1@example.com', 991)
+    member_2 = self.services.user.TestAddUser('member_2@example.com', 992)
+    member_3 = self.services.user.TestAddUser('member_3@example.com', 993)
+
+    expanded_group = self.services.user.TestAddUser('group@example.com', 999)
+    self.services.usergroup.CreateGroup(
+        'cnxn', self.services, expanded_group.email, 'owners')
+    self.services.usergroup.TestAddGroupSettings(
+        expanded_group.user_id,
+        expanded_group.email,
+        notify_members=True,
+        notify_group=False)
+    self.services.usergroup.TestAddMembers(
+        expanded_group.user_id, [member_1.user_id, member_2.user_id])
+
+    group = self.services.user.TestAddUser('group_1@example.com', 888)
+    self.services.usergroup.CreateGroup(
+        'cnxn', self.services, group.email, 'owners')
+    self.services.usergroup.TestAddGroupSettings(
+        group.user_id, group.email, notify_members=False, notify_group=True)
+    self.services.usergroup.TestAddMembers(
+        group.user_id, [member_2.user_id, member_3.user_id])
+
+    users_by_id = framework_views.MakeAllUserViews(
+        'cnxn', self.services.user, [
+            self.alice.user_id, self.fred.user_id, member_1.user_id,
+            member_2.user_id, member_3.user_id, group.user_id,
+            expanded_group.user_id
+        ])
+
+    comp_id = 123
+    self.config.component_defs = [
+        fake.MakeTestComponentDef(
+            self.project.project_id,
+            comp_id,
+            path='Chicken',
+            cc_ids=[group.user_id, expanded_group.user_id, self.alice.user_id])
+    ]
+    derived_cc_ids = [
+        self.fred.user_id,  # cc'd directly due to a rule
+        self.alice.user_id,  # cc'd due to the component
+        expanded_group
+        .user_id,  # cc'd due to the component, members notified directly
+        group.user_id,  # cc'd due to the component
+        # cc'd directly due to a rule,
+        # not removed from rule cc notifications due to transitive cc of
+        # expanded_group.
+        member_1.user_id,
+        member_3.user_id,
+    ]
+    issue = fake.MakeTestIssue(
+        self.project.project_id,
+        2,
+        'summary',
+        'New',
+        0,
+        derived_cc_ids=derived_cc_ids,
+        component_ids=[comp_id])
+    actual = notify_reasons.ComputeGroupReasonList(
+        'cnxn', self.services, self.project, issue, self.config, users_by_id,
+        [], True)
+
+    # Asserts list/reason of derived ccs from rules (not components).
+    # The derived ccs list/reason is the 7th tuple returned by
+    # ComputeGroupReasonList()
+    actual_ccd_apl, actual_ccd_reason = actual[6]
+    self.assertEqual(
+        actual_ccd_apl, [
+            notify_reasons.AddrPerm(
+                False, member_3.email, member_3, REPLY_NOT_ALLOWED,
+                user_pb2.UserPrefs(user_id=member_3.user_id)),
+            notify_reasons.AddrPerm(
+                False, self.fred.email, self.fred, REPLY_NOT_ALLOWED,
+                user_pb2.UserPrefs(user_id=self.fred.user_id)),
+            notify_reasons.AddrPerm(
+                False, member_1.email, member_1, REPLY_NOT_ALLOWED,
+                user_pb2.UserPrefs(user_id=member_1.user_id)),
+        ])
+    self.assertEqual(actual_ccd_reason, notify_reasons.REASON_DEFAULT_CCD)
+
+    # Asserts list/reason of derived ccs from components.
+    # The component derived ccs list/reason is hte 8th tuple returned by
+    # ComputeGroupReasonList() when there are component derived ccs.
+    actual_component_apl, actual_comp_reason = actual[7]
+    self.assertEqual(
+        actual_component_apl, [
+            notify_reasons.AddrPerm(
+                False, group.email, group, REPLY_NOT_ALLOWED,
+                user_pb2.UserPrefs(user_id=group.user_id)),
+            notify_reasons.AddrPerm(
+                False, self.alice.email, self.alice, REPLY_NOT_ALLOWED,
+                user_pb2.UserPrefs(user_id=self.alice.user_id)),
+            notify_reasons.AddrPerm(
+                False, member_2.email, member_2, REPLY_NOT_ALLOWED,
+                user_pb2.UserPrefs(user_id=member_2.user_id)),
+            notify_reasons.AddrPerm(
+                False, member_1.email, member_1, REPLY_NOT_ALLOWED,
+                user_pb2.UserPrefs(user_id=member_1.user_id)),
+        ])
+    self.assertEqual(
+        actual_comp_reason,
+        "You are auto-CC'd on all issues in component Chicken")
+
+  def testComputeGroupReasonList_Starrers(self):
+    """Bob and Alice starred it, but Alice opts out of notifications."""
+    self.alice.notify_starred_issue_change = False
+    actual = notify_reasons.ComputeGroupReasonList(
+        'cnxn', self.services, self.project, self.issue, self.config,
+        self.users_by_id, [], True,
+        starrer_ids=[self.alice.user_id, self.bob.user_id])
+    self.CheckGroupReasonList(
+        actual,
+        owner_apl=[notify_reasons.AddrPerm(
+            False, self.fred.email, self.fred, REPLY_NOT_ALLOWED,
+            user_pb2.UserPrefs(user_id=self.fred.user_id))],
+        starrer_apl=[notify_reasons.AddrPerm(
+            False, self.bob.email, self.bob, REPLY_NOT_ALLOWED,
+            user_pb2.UserPrefs(user_id=self.bob.user_id))])
+
+  def testComputeGroupReasonList_Subscribers(self):
+    """Bob subscribed."""
+    sq = tracker_bizobj.MakeSavedQuery(
+          1, 'freds issues', 1, 'owner:fred@example.com',
+          subscription_mode='immediate', executes_in_project_ids=[789])
+    self.services.features.UpdateUserSavedQueries(
+        'cnxn', self.bob.user_id, [sq])
+    actual = notify_reasons.ComputeGroupReasonList(
+        'cnxn', self.services, self.project, self.issue, self.config,
+        self.users_by_id, [], True)
+    self.CheckGroupReasonList(
+        actual,
+        owner_apl=[notify_reasons.AddrPerm(
+            False, self.fred.email, self.fred, REPLY_NOT_ALLOWED,
+            user_pb2.UserPrefs(user_id=self.fred.user_id))],
+        subscriber_apl=[notify_reasons.AddrPerm(
+            False, self.bob.email, self.bob, REPLY_NOT_ALLOWED,
+            user_pb2.UserPrefs(user_id=self.bob.user_id))])
+
+    # Now with subscriber notifications disabled.
+    actual = notify_reasons.ComputeGroupReasonList(
+        'cnxn', self.services, self.project, self.issue, self.config,
+        self.users_by_id, [], True, include_subscribers=False)
+    self.CheckGroupReasonList(
+        actual,
+        owner_apl=[notify_reasons.AddrPerm(
+            False, self.fred.email, self.fred, REPLY_NOT_ALLOWED,
+            user_pb2.UserPrefs(user_id=self.fred.user_id))])
+
+  def testComputeGroupReasonList_NotifyAll(self):
+    """Project is configured to always notify issues@example.com."""
+    self.project.issue_notify_address = 'issues@example.com'
+    actual = notify_reasons.ComputeGroupReasonList(
+        'cnxn', self.services, self.project, self.issue, self.config,
+        self.users_by_id, [], True)
+    self.CheckGroupReasonList(
+        actual,
+        owner_apl=[notify_reasons.AddrPerm(
+            False, self.fred.email, self.fred, REPLY_NOT_ALLOWED,
+            user_pb2.UserPrefs(user_id=self.fred.user_id))],
+        all_notifications_apl=[notify_reasons.AddrPerm(
+            False, 'issues@example.com', None, REPLY_NOT_ALLOWED,
+            user_pb2.UserPrefs())])
+
+    # We don't use the notify-all address when the issue is not public.
+    actual = notify_reasons.ComputeGroupReasonList(
+        'cnxn', self.services, self.project, self.issue, self.config,
+        self.users_by_id, [], False)
+    self.CheckGroupReasonList(
+        actual,
+        owner_apl=[notify_reasons.AddrPerm(
+            False, self.fred.email, self.fred, REPLY_NOT_ALLOWED,
+            user_pb2.UserPrefs(user_id=self.fred.user_id))])
+
+    # Now with the notify-all address disabled.
+    actual = notify_reasons.ComputeGroupReasonList(
+        'cnxn', self.services, self.project, self.issue, self.config,
+        self.users_by_id, [], True, include_notify_all=False)
+    self.CheckGroupReasonList(
+        actual,
+        owner_apl=[notify_reasons.AddrPerm(
+            False, self.fred.email, self.fred, REPLY_NOT_ALLOWED,
+            user_pb2.UserPrefs(user_id=self.fred.user_id))])